This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 11-338424, Nov. 29, 1999; and No. 2000-353147, Nov. 20, 2000, the entire contents of which are incorporated by reference.
The present invention relates to a microscope for sensing an image by an image sensing element.
Recently, demands have arisen for compact, space-saving microscopes which facilitate observation and operation. A known example of such a microscope is disclosed in Jpn. UM Appln. KOKAI Publication No. 3-96614 in which an illumination lamp is arranged at a lower portion of a microscope base, and a preparation holder, objective lens, and eyepiece lens are aligned along the optical axis above the illumination lamp to make it possible to observe, via the objective lens and eyepiece lens, a specimen image obtained through a preparation by transmission light from the illumination lamp.
In the microscope having this arrangement, a specimen image is observed via the eyepiece lens. The observer must look through the eyepiece lens every time he/she observes the specimen, and the motion is cumbersome.
To solve this problem, a microscope which displays a specimen image on an observation monitor is recently proposed. Jpn. Pat. Appln. KOKAI Publication No. 10-339845 discloses an example of such a microscope in which transmission light from a light source irradiates a specimen on a stage, a specimen image obtained through the specimen is formed on the image sensing surface of a TV camera via an objective lens, and the sensed image is displayed on a TV monitor.
In recent years, digital photographs are more frequently used even in the microscopic field along with the development of digital techniques. Compared to a silver halide photograph, a digital photograph can be easily taken without developing it, and left as data in a personal computer. The digital photograph does not degrade and require any space, unlike a negative.
In many cases, digital photographs were lower in image quality than silver halide photographs, and were hardly used. However, the development of image sensing elements (CCDs) has improved the image quality of digital photographs to be almost equal to that of silver halide photographs. Digital photographs are considered to be more popular in the future.
Various microscopes having image sensing elements have recently been proposed. An example of such a microscope is disclosed in Jpn. Pat. Appln. KOKAI Publication No. 11-264941 or 10-333055 in which a digital camera is connected to a conventional microscope, or an eyepiece lens is omitted to downsize a microscope.
In general, an image sensing element senses an image by accumulating or transferring (reading) charges. Most of the above-described digital microscopes control exposure only by an electronic shutter method of switching energization of an image sensing element and changing the exposure time. When a bright object is photographed, the image is exposed even during a short time while charges are read out from pixels, thus causing a smear that the object image is taken as if the object drew a stripe.
When the read method of the image sensing element is interlaced scanning, an image blurs or suffers misregistration due to the difference in read between scan lines.
For this reason, sometimes a high-quality image cannot be photographed (recorded).
In general, to solve this problem in the field of digital cameras, known techniques propose various digital cameras in which a shutter mechanism for physically shielding incident light on an image sensing element during charge read is arranged in front of the image sensing element.
However, in the above-mentioned microscope having an external TV camera and TV monitor, the TV camera and TV monitor are installed outside the microscope main body to make the whole apparatus bulky. This microscope has room for improvement in terms of downsizing and space reduction.
If this digital camera is connected to a microscope disclosed in Jpn. Pat. Appln. KOKAI Publication No. 11-264941, or a mechanical shutter mechanism is installed in front of the image sensing element of a microscope disclosed in Jpn. Pat. Appln. KOKAI Publication No. 10-333055, the above problem is solved, and an image improved in quality can be sensed (recorded).
In the microscope in which the shutter mechanism is installed in front of the image sensing element, the shutter mechanism is arranged on an imaging optical system. If the shutter mechanism is arranged on the imaging optical system, attention must be paid to deposition or entry of dust to the imaging optical system in assembly, and assembly requires a long time to increase the cost.
When the mechanical shutter is used as a shutter mechanism, the mechanical shutter mechanism is driven at a high speed to generate dust such as wear powder. This dust is deposited on a lens on the imaging optical system to degrade a photographed image.
As the resolution of the image sensing element increases in the future, these problems become more serious, and cause fatal defects particularly in the microscopic field in which a high-resolution image is required.
The present invention has been made in consideration of the above situation, and has as its object to provide a compact, space-saving microscope which facilitates observation and operation.
The present invention has been made in consideration of the above situation, and has as another object to provide a low-cost microscope capable of photographing a high-quality image without any image degradation or any assembly problem caused by arranging a shutter mechanism on an imaging optical system.
The first invention is characterized by comprising an LED light source, a stage for placing a specimen irradiated with light from the LED light source, a lens barrel which is arranged to face the specimen on the stage, and has an observation optical system for acquiring an observation image of the specimen, an image sensing element which is arranged at an imaging position of the observation optical system of the lens barrel, and senses the observation image of the specimen, an electrical processing unit for processing an output signal from the image sensing element, a monitor for displaying image data of the observation image output from the electrical processing unit, and recording means for recording the image data of the observation image, wherein the LED light source, the stage, the lens barrel, and the image sensing element are linearly aligned, and the electrical processing unit is arranged behind the lens barrel.
The second invention according to the first invention is characterized in that the second invention further comprises a support member which stands almost upright, and the LED light source, the stage, the lens barrel, and the image sensing element are supported along the support member.
The third invention is a transmission illumination microscope characterized by comprising a light source, a stage for placing a specimen irradiated with illumination light from the light source, an imaging optical system which is arranged to face the specimen on the stage, and acquires an observation image of the specimen, an image sensing element arranged at an imaging position of the imaging optical system, a control unit for controlling the image sensing element, and a shutter mechanism which is arranged between the light source and the stage, and shields incident light on the image sensing element in synchronism with an image sensing timing of the image sensing element controlled by the control unit.
The fourth invention is a coaxial incident-light illumination microscope characterized by comprising a light source, a stage for placing a specimen irradiated with illumination light from the light source, an imaging optical system which is arranged to face the specimen on the stage, and acquires an observation image of the specimen, an image sensing element arranged at an imaging position of the imaging optical system, a control unit for controlling the image sensing element, a semi-transmission reflecting member for irradiating the specimen with illumination light from the light source coaxially with the observation optical system, a light-transmitting dustproof member interposed between the light source and the semi-transmission reflecting member, and a shutter mechanism which is arranged between the light source and the light-transmitting dustproof member, and shields incident light on the image sensing element in synchronism with an image sensing timing of the image sensing element controlled by the control unit.
According to the first invention, the observation image of the specimen can be observed on the monitor, so that specimen observation and its operation can be facilitated. The LED light source, stage, lens barrel, and image sensing element are aligned, and the electrical processing unit is arranged behind the lens barrel. This can downsize the overall microscope.
According to the second invention, the LED light source, stage, lens barrel, and image sensing element are arranged along the support member which stands almost upright, which can further downsize the overall microscope.
According to the third and fourth inventions, an assembly problem caused by arranging the shutter mechanism on the imaging optical system does not arise, and dust such as wear powder generated from the shutter mechanism or the like does not deposit on the imaging optical system. Thus, an apparatus capable of photographing a high-quality image can be provided at a low cost.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.